1. Technical Field
The present invention relates to a provisioning device which is provided in a plant and performs provisioning for setting, in advance, in a field device to newly join a wireless network that serves for exchange of data with field devices, information that are necessary for joining of the field device. The present invention relates to a provisioning device capable of performing provisioning for a field device reliably and efficiently.
2. Related Art
Conventionally, in a trial run of field devices which are cable-connected to a distributed control system and analog transmission as typified by a type using an 4 to 20 mA analog signal or digital transmission used in a specification of the field bus association, the field devices are adjusted and checked (pre-installation checks) before they are connected and final checks such as feedback control loop checks of PID control are performed (called commissioning) after they are connected.
Various kinds of field devices such as a differential pressure gauge, a flowmeter, a thermometer, a monitoring camera, an actuator, and a controller are installed in plants.
Nowadays, techniques that make it possible to use wireless transmission lines in a case that wired transmission lines would be used conventionally are being established in the process control field. In particular, a configuration with wireless connections in which field devices are connected by a wireless transmission scheme as typified by the ISA 100.11a standard is being studied.
For example, it is proposed to configure a process control system of industrial automation utilizing a wireless control network system (hereinafter referred to as a wireless network) that is provided with field devices.
This is to solve a problem the control accuracy of conventional control systems is lowered because sensors for measuring temperatures, flow rates, etc. cannot be installed at optimum positions in a plant because of limitations of communication distances, restrictions relating to wiring, and other reasons which result from the fact that the conventional control systems employ wired networks.
To newly add a field device to a wireless network, work (called provisioning) of setting security information and network information in the field device in advance is necessary.
The provisioning is an act of setting, in advance, in a field device, information (security information and network information) that are necessary for joining the field device in a wireless network so as to prevent illegal access by a third person for falsification of data, masquerading, etc.
A field device in which no such setting information is set or such setting information are set erroneously cannot join a wireless network.
Security information includes a join key. Network information is information that is necessary for joining of a field device in a wireless network.
The wireless communication standards for a wireless network that are under examination are WirelessHART which is prescribed in HART (Highway Addressable Remote Transducer) 7 and the process control wireless communication standard ISA 100.11a which was approved by the ISA 100 committee of ISA (International Society of Automation).
WirelessHART and ISA 100.11a are industrial wireless communication protocols/standards for frequency division communication, the details of which are described in the following documents, for example:
Document 1: “Wireless systems for industrial automation: Process control and related applications”
Document 2: “Control with WirelessHART”(URL: http://www.hartcomm.org/protocol/training/resources/wiHART_resources/Control_with_WirelessHART.pdf)
A device which performs provisioning for a field device is called a provisioning device. A conventional provisioning device will be described below.
FIG. 4 is a block diagram showing functions of an example conventional provisioning device.
The provisioning device 1 is a device for performing provisioning on field devices 2-4, and includes: a receiver 11 such as a keyboard and a mouse for receiving an operation from a user who performs provisioning operation for the field devices 2-4; a wireless communication unit 12 for exchanging data with the field devices 2-4 by wireless communication such as infrared communication; a device information acquiring unit 13 for acquiring unique information (device tag, device EUI64, vendor ID, and device type) from each of the field devices 2-4 by wireless communication; a display unit 14 for displaying an operation screen for provisioning and the acquired unique information of each of the field devices 2-4; and a computation controller 15 for controlling the individual units to perform a provisioning operation.
The device EUI64 is an identifier for identification of a field device, “EUI64” being an abbreviation of “64-bit extended unique identifier.”
The field devices 2-4 are field devices that are installed in a plant, for example, and are to be newly added to a wireless network that involves field devices that exchange data by wireless communication.
In the following, a user who performs provisioning for the field devices 2-4 by operating the provisioning device 1 will be referred to as a field worker.
A field worker has a white list in which the unique information of the field devices 2-4 and data for provisioning of the field devices 2-4 (hereinafter referred to as “provisioning data”) are correlated with each other in advance. In other words, the white list is a correspondence table containing the unique information of the field devices 2-4 and the provisioning data.
For example, each set of provisioning data contained in the white list includes a network ID of the wireless network to which the field devices 2-4 are to be added, a device address, on the wireless network, of a system manager apparatus (not shown) to which a joining request is sent in adding each of the field device 2-4 to the wireless network, and a join key which is used for authentication in adding each of the field devices 2-4 to the wireless network.
The white list may be any of a database, electronic data in text form, and information written on a sheet as long as it correlates the unique information and the provisioning data.
As described above, the conventional provisioning device 1 operates in the following manner FIG. 5 illustrates how the conventional provisioning device 1 operates.
At step SP101, a field worker inputs information (e.g., device tag and network ID) for identification of a provisioning subject field device (e.g., field device 2) through the receiver 11 into an input area of the operation screen displayed on the display unit 14.
In other words, the provisioning device 1 receives the information (e.g., device tag and network ID) for identification of the provisioning subject field device 2 through the receiver 11.
At step SP102, the device information acquiring unit 13 controls the wireless communication unit 12 and thus sends, to the field device 2, by wireless communication (e.g., infrared communication), a request signal for requesting transmission of the unique information of the field device 2.
Receiving the request signal, at step SP103 the field device 2 sends the unique information by wireless communication (e.g., infrared communication).
In the provisioning device 1, when receiving the unique information of the field device 2 through the wireless communication unit 12, at step SP104 the computation controller 16 displays the unique information of the field device 2 on the display unit 14.
At step SP105, the field worker extracts the provisioning data to be set in the field device 2 from the white list based on particular information (e.g., information that are readable but not writable such as the device EUI64, vendor ID, and device type) among the unique information of the field device 2 being displayed on the display unit 14.
At step SP106, the field worker inputs the extracted provisioning data through the receiver 11.
In other words, the provisioning data for the field device 3 that have been extracted by the field worker are input to the provisioning device 1 through the receiver 11.
At step SP107, the computation controller 16 of the provisioning device 1 sends the provisioning data received through the receiver 11 to the field device 2 through the wireless communication unit 12.
At step SP108, a computation controller (not shown) of the field device 2 sets the network ID, the device address, on the wireless network, of the system manager apparatus, and the join key based on the received provisioning data and stores them in a storage unit (not shown).
At step SP109, the computation controller of the field device 2 sends currently set information to the provisioning device 1 by wireless communication.
At step SP110, the provisioning device 1 receives the currently set information from the field device 2 through the wireless communication unit 12 and displays them on the display unit 14.
At step SP111, the field worker visually compares the information that are currently set in the field device 2 and displayed on the display unit 14 with the provisioning data to be set in the field device 2 that are contained in the white list, and determines whether the two sets of information are identical or not. If they are identical, the field worker determines that the provisioning data have been set normally. The provisioning work for the field device 2 is thus finished.
Upon the completion of the provisioning for the field device 2, provisioning for the field device 3 is performed. Upon completion of the provisioning for the field device 3, provisioning for the field device 4 is performed.
The provisioning work for each of the field devices 3 and 4 is the same as the above-described operation (SP101-SP111) and hence will not be described below.
As described above, in the conventional provisioning device 1, provisioning data that are contained in the white list in advance and input by a field worker are transmitted to a field device by wireless communication. The field device performs setting based on the received provisioning data. As a result, the field device can newly join a wireless network without risk of illegal access for falsification of data, masquerading, or the like.
For example, JP-A-2009-145934 relates to a provisioning device and discloses a technique for visually checking an inside state of a pipe using a capsule imaging device.
However, the conventional provisioning device 1 has a problem that a human error such as an erroneous input tends to occur, because a field worker inputs setting information based on provisioning data that are extracted from the white list. This results in a problem that if setting information erroneously that was input erroneously due to a human error is kept set in a field device, the field device cannot join the wireless network.
There is another problem that since many types of field device are installed in a large number in a plant, an error tends to occur in extracting proper provisioning data from the white list or inputting proper provisioning data, in which case the provisioning cannot be performed properly.
Whereas a large number of field devices are installed in a plant, with the conventional provisioning device 1 provisioning work is performed for only one field device at a time. This means a problem that the work efficiency is low.
Provisioning data include data that is important in terms of security. However, in a situation that as with the conventional provisioning device 1 a field worker carries the white list, the field worker may, for example, lose the white list (human error) or be robbed of it. A malicious third person who has acquired the white list may use it to, for example, access the wireless network illegally. This means a problem that a fatal security hole may be produced.